Small Animal Simulation Studies using the microPET® FOCUS System and the GATE Platform

GATE, a Monte Carlo simulation platform dedicated to nuclear medicine, has been validated for modeling μPET systems like the microPET® FOCUS 220 under realistic imaging conditions. In this paper, the use of the microPET® FOCUS 220 simulation model with GATE is used along with realistic mouse phantoms (including respiratory motion) and radioactive distribution maps, obtained from real exams, to produce simulated PET data of a mouse. We present results from simulated realistic whole body studies of the mouse with [18F]fluoride and 2-Deoxy-[18F]fluoro-D-glucose (FDG) and compare them to real data. The simulations were performed using voxelized mouse phantoms, obtained from real PET examinations and from digital mouse anatomical models. Respiratory motion is introduced in the simulation process. The qualitative and quantitative results from simulated data reproduce real values within 23%. This discrepancy can be related with specificities of simulated and real data, in particular due to attenuation and scattering corrections.